Pinned topicExpected usage when a module alias is called

‏2012-12-24T19:29:25Z
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I opened a PMR with IBM asking how they would expect TADz to report usage for a given situation. I can already see what results I am actually getting, but want to know from IBM what I should expect (then I would know if what I am seeing is expected or not because I thought in the past I was getting different results). IBM directed me to this site to get this question answered, so here I am. Here is the question posed to IBM:

Hello, we are running TAD/z V7.5 and have a question about where we
would expect to see module usage when calling a module alias. So the
setup is this, there is a real module named PC2V260, and this module
also has an alias to it called MSSPC2.
So if jobs are run that call/execute the PGM=MSSPC2, what usage should
we expect to see in TADz?
1) Usage on MSSPC2 only
2) Usage on PC2V260 only
3) Usage on both MSSPC2 and PC2V260

Re: Expected usage when a module alias is called

‏2013-01-17T06:03:10Z

This is the accepted answer.
This is the accepted answer.

Hi,

The PMR was answered, but because the answer may be of interest to others I'll post a response here.

Firstly, if the program is not re-entrant then the usage will be reported under the invocation name because that is the only name the system uses.
So, if the program is invoked by its real name then UMON will log the real name.
If the program is invoked using an alias name then UMON will log the alias name.

For re-entrant programs, the system always finds out the real name, and if the program was invoked using an alias name then the system will know that name too.
In this case, UMON generally reports the usage under the real name.

The reason it is "generally" and not "always" is that not all UMON data collection points have access to the real name. If the daily switch occurs at a time such that the program usage has been detected only by that UMON data collection point, then the usage will be reported under the alias name - because that is the only name known by UMON at switch time.

In the general case, once the usage has been captured by a UMON data collection point that can determine the real name, the usage is logged by UMON under the real name.

Ideally from our p-o-v, we would always use the real names for re-entrant programs and alias names could be ignored. That was the case until we added the data collection point which does not know the real names of aliases. UMON does always use the real names for LPA programs.

One major reason we prefer dealing with real names is that their names usually obey component naming conventions more strictly - look at SYS1.CMDLIB to see that - which makes it simpler for customers to manage their name inclusion and exclusion filtering.